a) Field of the Invention
The present invention relates to a microscope, and more specifically to a surgical microscope comprising a stand, an arm attached to the stand for sustaining the surgical microscope at the tip thereof and an electric equipment.
b) Description of the Prior Art
Medical instruments such as surgical microscopes must have reliability and security due to the nature inherent therein. Speaking concretely, the medical instruments of this type must be rarely troubled, and, should a function be troubled, cause no influence on the other functions and be repairable easily and in a short time.
FIG. 1 illustrates an example of the electric equipment of the conventionally known surgical microscopes. The electric equipment consists of a motor-driven magnification adjustment means 1 for changing magnification of the microscope, a motor-driven focusing means 2 for focusing the microscope, a lamp means 3 for illuminating with lamps, a control means 4 for performing motor controls of the magnification adjustment means 1 and the focusing means 2 as well as brightness control and ON/OFF control of the lamp means 3, and a power source means 5 for supplying electric power to said control means 4. The power source means 5 is generally so adapted as to receive electric power from a commerical line power source 6, convert the power into control voltages and driving voltages for the motors and lamps, and then supply the voltages to the control means 4. Further, signals and powers from the control means 4 to the magnification adjustment means 1, the focusing means 2 and the lamp means 3 are supplied through connectors arranged on the tip of an arm (not shown) sustaining the microscope.
Let us now assume that a magnification adjustment motor arranged in the magnification adjustment means is locked and an overcurrent flows to the circuit. Though the circuit and parts are normally protected with protectors such as fuses, the power source means 5 is troubled in the worst case. Under such a circumstance, electric power is not supplied to the control means 4 from the power source means 5 and the entire electric equipment stops functioning. Speaking concretely, not only the magnification adjustment means 1 but also the focusing means 2 does not operate and the lamp means 3 is extinguished. Since most of the functions of the surgical microscope are now electrically operated, surgical operation is influenced rather seriously by the stopping of all the functions of the electric equipment and may not be continued in certain cases. Especially, the illumination with the lamps is indispensable for surgical operation and extinguishment of the lamp means may cause vital result. In addition, in the configuration shown in FIG. 1, the control means 4 must receive three to six voltages at different levels, thereby requiring the power source means 5 having large dimensions. Further, since the control means 4 is generally integrated with the power source means 5 for practical instrumentation in such a configuration, the power source means has larger dimensions. Accordingly, the power source means 5 cannot be repaired or restored speedily in case of a trouble occurring therein since troubleshooting in such a large power source means requires time-consuming checks in a broad range or replacement of such large power source means as a whole with a new one requires tough works.
In the recent years where ME (medical electronics) has made a great progress and different medical sections use the ME instruments unique thereto, the power sources for these instruments and connecting cables therefor are scattered around the site of surgical operation, thereby causing great hindrance on working convenience of surgical operators and assistants. It is desirable to build the power source means for the various component units into a surgical microscope and supply electric powers to the component units through connectors arranged at the tip of the arm, like the connectors attached to the tip of the arm for an auxiliary illuminator of the conventional surgical microscopes. Such a design will serve for making tidy the site of surgical operation by eliminating the power sources and connecting cables which are currently scattered around the site of surgical operation.
When it is assumed that each medical section uses two to five types of medical instruments most of which are unique thereto, there are placed a large number of medical instruments at a site of surgical operation. Accordingly, a surgical microscope designed on the basis of the configuration of the conventional surgical microscope and for use common to different medical sections must inevitably be equipped with more than ten power sources and more than ten connectors, thereby posing a problem that the surgical microscope will inevitably have large dimensions. Further, the connecting cable will inevitably be thickened, thereby posing another problem that the arm comprising such a connecting cable will have low operability.